Blood pump shaft bearing

Abstract

A blood pump includes an impeller; a drive shaft coupled to the impeller and configured to rotate with the impeller; a motor configured to drive the impeller; and a bearing assembly disposed adjacent the motor and configured to receive an end of the drive shaft. The bearing assembly includes a bearing, where the end of the drive shaft is at least partially rounded, and the where the bearing includes a concave depression defined in a first side of the bearing, where the depression is configured to receive the end of the drive shaft. The bearing assembly may include a lubricant chamber configured to hold a lubricant.

We claim: 
     
       1. A blood pump, comprising:
 an impeller; 
 a drive shaft coupled to the impeller and configured to rotate with the impeller, the drive shaft comprising an at least partially rounded end; 
 a motor configured to drive the impeller; and 
 a bearing assembly disposed adjacent the motor and configured to receive the at least partially rounded end of the drive shaft, the bearing assembly comprising a bearing and a lubricant chamber configured to hold a lubricant, the bearing including a concave depression defined in a first side of the bearing, the depression being configured to receive the at least partially rounded end of the drive shaft, and the lubricant chamber comprising at least one channel defined in a second side of the bearing, the at least one channel extending transversely relative to and intersecting with the depression, wherein the at least one channel is configured to retain the lubricant. 
 
     
     
       2. The blood pump of  claim 1 , wherein the at least one channel is a first channel, and further comprising a second channel intersecting the first channel in the depression, wherein the second channel is configured to retain lubricant. 
     
     
       3. The blood pump of  claim 2 , wherein the second channel extends transversely relative to the first channel. 
     
     
       4. A blood pump, comprising:
 an impeller; 
 a drive shaft coupled to the impeller and configured to rotate with the impeller; 
 a motor configured to drive the impeller; and 
 a proximal bearing assembly disposed adjacent the motor and configured to receive an end of the drive shaft, the proximal bearing assembly comprising a proximal bearing, wherein the end of the drive shaft is at least partially rounded, and wherein the proximal bearing includes a concave depression defined in a first side of the proximal bearing, wherein the depression is configured to receive the end of the drive shaft; 
 a distal bearing assembly comprising a cylindrical-shaped bearing at an intersection of the drive shaft and a stationary shaft mounting pin, wherein the drive shaft is configured to rotate with respect to the stationary shaft mounting pin, and wherein a lubricant chamber configured to hold a lubricant is defined between an inner surface of the cylindrical-shaped bearing and an outer surface of the stationary shaft mounting pin. 
 
     
     
       5. The blood pump of  claim 4 , the proximal bearing assembly further comprising a cup washer having a base and peripheral wall extending away from the base, forming a cavity bounded by an inner surface of the peripheral wall and an inner surface of the base, wherein the proximal bearing is configured to be at least partially disposed within the cavity. 
     
     
       6. The blood pump of  claim 5 , the cup washer further comprising a shaft aperture defined in the base of the cup washer, extending from the outer surface of the base to the inner surface of the base, wherein the shaft aperture is configured to receive a portion of the drive shaft. 
     
     
       7. The blood pump of  claim 5 , wherein the lubricant chamber is a distal lubricant chamber, and at least a portion of a proximal lubricant chamber is defined between the inner surface of the peripheral wall of the cup washer, the inner surface of the base of the cup washer, and a first side of the proximal bearing. 
     
     
       8. The blood pump of  claim 5 , wherein the proximal lubricant chamber is at least partially defined within the proximal bearing. 
     
     
       9. The blood pump of  claim 8 , the proximal lubricant chamber comprising at least one channel defined in a second side of the bearing, the at least one channel passing through the depression, wherein the at least one channel is configured to retain lubricant. 
     
     
       10. The blood pump of  claim 9 , the at least one channel comprising two channels that intersect one another in the depression.